Adds support to open local repositories and to use file-based object storage (#55)v3.1.0

* remove some comments

* idx writer/reader

* Shut up ssh tests, they are annoying

* Add file scheme test to clients

* Add dummy file client

* Add test fot file client

* Make tests use fixture endpoint

* add parser for packed-refs format

* add parser for packed-refs format

* WIP adding dir.Refs() tests

* Add test for fixture refs

* refs parser for the refs directory

* Documentation

* Add Capabilities to file client

* tgz.Exatract now accpets a path instead of a Reader

* fix bug in idxfile fanout calculation

* remove dead code

* packfile documentation

* clean packfile parser code

* add core.Object.Content() and returns errors for core.ObjectStorage.Iter()

* add seekable storage

* add dir repos to NewRepository

* clean prints

* Add dir client documentation to README

* Organize the README

* README

* Clean tgz package

* Clean temp dirs after tgz tests

* Gometalinter on gitdir

* Clean pattern function

* metalinter tgz

* metalinter gitdir

* gitdir coverage and remove seekable packfile filedescriptor leak

* gitdir Idxfile tests and remove file descriptor leak

* gitdir Idxfile tests when no idx is found

* clean storage/seekable/internal/index and some formats/idxfile API issues

* clean storage/seekable

* clean formats/idx

* turn packfile/doc.go into packfile/doc.txt

* move formats/packfile/reader to decoder

* fix packfile decoder error names

* improve documentation

* comment packfile decoder errors

* comment public API (format/packfile)

* remve duplicated code in packfile decoder test

* move tracking_reader into an internal package and clean it

* use iota for packfile format

* rename packfile parse.go to packfile object_at.go

* clean packfile deltas

* fix delta header size bug

* improve delta documentation

* clean packfile deltas

* clean packfiles deltas

* clean repository.go

* Remove go 1.5 from Travis CI

Because go 1.5 does not suport internal packages.

* change local repo scheme to local://

* change "local://" to "file://" as the local scheme

* fix broken indentation

* shortens names of variables in short scopes

* more shortening of variable names

* more shortening of variable names

* Rename git dir client to "file", as the scheme used for it

* Fix file format ctor name, now that the package name has change

* Sortcut local repo constructor to not use remotes

The object storage is build directly in the repository ctor, instead
of creating a remote and waiting for the user to pull it.

* update README and fix some errors in it

* remove file scheme client

* Local respositories has now a new ctor

This is, they are no longer identified by the scheme of the URL, but are
created different from inception.

* remove unused URL field form Repository

* move all git dir logic to seekable sotrage ctor

* fix documentation

* Make formats/file/dir an internal package to storage/seekable

* change package storage/seekable to storage/fs

* clean storage/fs

* overall storage/fs clean

* more cleaning

* some metalinter fixes

* upgrade cshared to last changes

* remove dead code

* fix test error info

* remove file scheme check from clients

* fix test error message

* fix test error message

* fix error messages

* style changes

* fix comments everywhere

* style changes

* style changes

* scaffolding and tests for local packfiles without ifx files

* outsource index building from packfile to the packfile decoder

* refactor packfile header reading into a new function

* move code to generate index from packfile back to index package

* add header parsing

* fix documentation errata

* add undeltified and OFS delta support for index building from the packfile

* add tests for packfile with ref-deltas

* support for packfiles with ref-deltas and no idx

* refactor packfile format parser to reuse code

* refactor packfile format parser to reuse code

* refactor packfile format parser to reuse code

* refactor packfile format parser to reuse code

* refactor packfile format parser to reuse code

* WIP refactor packfile format parser to reuse code

* refactor packfile format parser to reuse code

* remove prints from tests

* remove prints from tests

* refactor packfile.core into packfile.parser

* rename packfile reader to something that shows it is a recaller

* rename cannot recall error

* rename packfile.Reader to packfile.ReadRecaller and document

* speed up test by using StreamReader instead of SeekableReader when possible

* clean packfile StreamReader

* stream_reader tests

* refactor packfile.StreamReader into packfile.StreamReadRecaller

* refactor packfile.SeekableReader into packfile.SeekableReadRecaller and document it

* generalize packfile.StreamReadRecaller test to all packfile.ReadRecaller implementations

* speed up storage/fs tests

* speed up tests in . by loading packfiles in memory

* speed up repository tests by using and smaller fixture

* restore doc.go files

* rename packfile.ReadRecaller implementations to shorter names

* update comments to type changes

* packfile.Parser test (WIP)

* packfile.Parser tests and add ForgetAll() to packfile.ReadRecaller

* add test for packfile.ReadRecaller.ForgetAll()

* clarify seekable being able to recallByOffset forgetted objects

* use better names for internal maps

* metalinter packfile package

* speed up some tests

* documentation fixes

* change storage.fs package name to storage.proxy to avoid confusion with new filesystem support

* New fs package and os transparent implementation

Now NewRepositoryFromFS receives a fs and a path and tests are
modified accordingly, but it is still not using for anything.

* add fs to gitdir and proxy.store

* reduce fs interface for easier implementation

* remove garbage dirs from tgz tests

* change file name gitdir/dir.go to gitdir/gitdir.go

* fs.OS tests

* metalinter utils/fs

* add NewRepositoryFromFS documentation to README

* Readability fixes to README

* move tgz to an external dependency

* move filesystem impl. example to example dir

* rename proxy/store.go to proxy/storage.go for coherence with memory/storage.go

* rename proxy package to seekable

1 files changed, 326 insertions, 0 deletions

diff --git a/storage/seekable/storage_test.go b/storage/seekable/storage_test.go
new file mode 100644
index 0000000..bc0ad3d
--- /dev/null
+++ b/storage/seekable/storage_test.go
@@ -0,0 +1,326 @@
+package seekable_test
+
+import (
+	"fmt"
+	"os"
+	"reflect"
+	"sort"
+	"testing"
+
+	"gopkg.in/src-d/go-git.v3/core"
+	"gopkg.in/src-d/go-git.v3/formats/packfile"
+	"gopkg.in/src-d/go-git.v3/storage/memory"
+	"gopkg.in/src-d/go-git.v3/storage/seekable"
+	"gopkg.in/src-d/go-git.v3/storage/seekable/internal/gitdir"
+	"gopkg.in/src-d/go-git.v3/utils/fs"
+
+	"github.com/alcortesm/tgz"
+	. "gopkg.in/check.v1"
+)
+
+func Test(t *testing.T) { TestingT(t) }
+
+type FsSuite struct{}
+
+var _ = Suite(&FsSuite{})
+
+var fixtures map[string]string // id to git dir paths (see initFixtures below)
+
+func fixture(id string, c *C) string {
+	path, ok := fixtures[id]
+	c.Assert(ok, Equals, true, Commentf("fixture %q not found", id))
+
+	return path
+}
+
+var initFixtures = [...]struct {
+	id  string
+	tgz string
+}{
+	{
+		id:  "binary-relations",
+		tgz: "internal/gitdir/fixtures/alcortesm-binary-relations.tgz",
+	}, {
+		id:  "binary-relations-no-idx",
+		tgz: "internal/gitdir/fixtures/alcortesm-binary-relations-no-idx.tgz",
+	}, {
+		id:  "ref-deltas-no-idx",
+		tgz: "internal/gitdir/fixtures/ref-deltas-no-idx.tgz",
+	},
+}
+
+func (s *FsSuite) SetUpSuite(c *C) {
+	fixtures = make(map[string]string, len(initFixtures))
+	for _, init := range initFixtures {
+		path, err := tgz.Extract(init.tgz)
+		c.Assert(err, IsNil, Commentf("error extracting %s\n", init.tgz))
+		fixtures[init.id] = path
+	}
+}
+
+func (s *FsSuite) TearDownSuite(c *C) {
+	for _, v := range fixtures {
+		err := os.RemoveAll(v)
+		c.Assert(err, IsNil, Commentf("error removing fixture %q\n", v))
+	}
+}
+
+func (s *FsSuite) TestNewErrorNotFound(c *C) {
+	fs := fs.NewOS()
+	_, err := seekable.New(fs, "not_found/.git")
+	c.Assert(err, Equals, gitdir.ErrNotFound)
+}
+
+func (s *FsSuite) TestHashNotFound(c *C) {
+	path := fixture("binary-relations", c)
+
+	fs := fs.NewOS()
+	gitPath := fs.Join(path, ".git/")
+
+	sto, err := seekable.New(fs, gitPath)
+	c.Assert(err, IsNil)
+
+	_, err = sto.Get(core.ZeroHash)
+	c.Assert(err, Equals, core.ErrObjectNotFound)
+}
+
+func (s *FsSuite) TestGetCompareWithMemoryStorage(c *C) {
+	for i, fixId := range [...]string{
+		"binary-relations",
+		"binary-relations-no-idx",
+		"ref-deltas-no-idx",
+	} {
+		path := fixture(fixId, c)
+		com := Commentf("at subtest %d, (fixture id = %q, extracted to %q)",
+			i, fixId, path)
+
+		fs := fs.NewOS()
+		gitPath := fs.Join(path, ".git/")
+
+		memSto, err := memStorageFromGitDir(fs, gitPath)
+		c.Assert(err, IsNil, com)
+
+		seekableSto, err := seekable.New(fs, gitPath)
+		c.Assert(err, IsNil, com)
+
+		equal, reason, err := equalsStorages(memSto, seekableSto)
+		c.Assert(err, IsNil, com)
+		c.Assert(equal, Equals, true,
+			Commentf("%s - %s\n", com.CheckCommentString(), reason))
+	}
+}
+
+func memStorageFromGitDir(fs fs.FS, path string) (*memory.ObjectStorage, error) {
+	dir, err := gitdir.New(fs, path)
+	if err != nil {
+		return nil, err
+	}
+
+	fs, packfilePath, err := dir.Packfile()
+	if err != nil {
+		return nil, err
+	}
+
+	f, err := fs.Open(packfilePath)
+	if err != nil {
+		return nil, err
+	}
+
+	sto := memory.NewObjectStorage()
+	r := packfile.NewStream(f)
+	d := packfile.NewDecoder(r)
+	err = d.Decode(sto)
+	if err != nil {
+		return nil, err
+	}
+
+	err = f.Close()
+	if err != nil {
+		return nil, err
+	}
+
+	return sto, nil
+}
+
+func equalsStorages(a, b core.ObjectStorage) (bool, string, error) {
+	for _, typ := range [...]core.ObjectType{
+		core.CommitObject,
+		core.TreeObject,
+		core.BlobObject,
+		core.TagObject,
+	} {
+		iter, err := a.Iter(typ)
+		if err != nil {
+			return false, "", fmt.Errorf("cannot get iterator: %s", err)
+		}
+
+		for {
+			ao, err := iter.Next()
+			if err != nil {
+				iter.Close()
+				break
+			}
+
+			bo, err := b.Get(ao.Hash())
+			if err != nil {
+				return false, "", fmt.Errorf("getting object with hash %s: %s",
+					ao.Hash(), err)
+			}
+
+			equal, reason, err := equalsObjects(ao, bo)
+			if !equal || err != nil {
+				return equal, reason, fmt.Errorf("comparing objects: %s", err)
+			}
+		}
+	}
+
+	return true, "", nil
+}
+
+func equalsObjects(a, b core.Object) (bool, string, error) {
+	ah := a.Hash()
+	bh := b.Hash()
+	if ah != bh {
+		return false, fmt.Sprintf("object hashes differ: %s and %s\n",
+			ah, bh), nil
+	}
+
+	atyp := a.Type()
+	btyp := b.Type()
+	if atyp != btyp {
+		return false, fmt.Sprintf("object types differ: %d and %d\n",
+			atyp, btyp), nil
+	}
+
+	asz := a.Size()
+	bsz := b.Size()
+	if asz != bsz {
+		return false, fmt.Sprintf("object sizes differ: %d and %d\n",
+			asz, bsz), nil
+	}
+
+	ac := a.Content()
+	if ac != nil {
+		bc := b.Content()
+		if !reflect.DeepEqual(ac, bc) {
+			return false, fmt.Sprintf("object contents differ"), nil
+		}
+	}
+
+	return true, "", nil
+}
+
+func (s *FsSuite) TestIterCompareWithMemoryStorage(c *C) {
+	for i, fixId := range [...]string{
+		"binary-relations",
+		"binary-relations-no-idx",
+		"ref-deltas-no-idx",
+	} {
+
+		path := fixture(fixId, c)
+		com := Commentf("at subtest %d, (fixture id = %q, extracted to %q)",
+			i, fixId, path)
+
+		fs := fs.NewOS()
+		gitPath := fs.Join(path, ".git/")
+
+		memSto, err := memStorageFromDirPath(fs, gitPath)
+		c.Assert(err, IsNil, com)
+
+		seekableSto, err := seekable.New(fs, gitPath)
+		c.Assert(err, IsNil, com)
+
+		for _, typ := range [...]core.ObjectType{
+			core.CommitObject,
+			core.TreeObject,
+			core.BlobObject,
+			core.TagObject,
+		} {
+
+			memObjs, err := iterToSortedSlice(memSto, typ)
+			c.Assert(err, IsNil, com)
+
+			seekableObjs, err := iterToSortedSlice(seekableSto, typ)
+			c.Assert(err, IsNil, com)
+
+			for i, o := range memObjs {
+				c.Assert(seekableObjs[i].Hash(), Equals, o.Hash(), com)
+			}
+		}
+	}
+}
+
+func memStorageFromDirPath(fs fs.FS, path string) (*memory.ObjectStorage, error) {
+	dir, err := gitdir.New(fs, path)
+	if err != nil {
+		return nil, err
+	}
+
+	fs, packfilePath, err := dir.Packfile()
+	if err != nil {
+		return nil, err
+	}
+
+	sto := memory.NewObjectStorage()
+	f, err := fs.Open(packfilePath)
+	if err != nil {
+		return nil, err
+	}
+
+	r := packfile.NewStream(f)
+	d := packfile.NewDecoder(r)
+	err = d.Decode(sto)
+	if err != nil {
+		return nil, err
+	}
+
+	if err = f.Close(); err != nil {
+		return nil, err
+	}
+
+	return sto, nil
+}
+
+func iterToSortedSlice(storage core.ObjectStorage, typ core.ObjectType) ([]core.Object,
+	error) {
+
+	iter, err := storage.Iter(typ)
+	if err != nil {
+		return nil, err
+	}
+
+	r := make([]core.Object, 0)
+	for {
+		obj, err := iter.Next()
+		if err != nil {
+			iter.Close()
+			break
+		}
+		r = append(r, obj)
+	}
+
+	sort.Sort(byHash(r))
+
+	return r, nil
+}
+
+type byHash []core.Object
+
+func (a byHash) Len() int      { return len(a) }
+func (a byHash) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+func (a byHash) Less(i, j int) bool {
+	return a[i].Hash().String() < a[j].Hash().String()
+}
+
+func (s *FsSuite) TestSet(c *C) {
+	path := fixture("binary-relations", c)
+
+	fs := fs.NewOS()
+	gitPath := fs.Join(path, ".git/")
+
+	sto, err := seekable.New(fs, gitPath)
+	c.Assert(err, IsNil)
+
+	_, err = sto.Set(&memory.Object{})
+	c.Assert(err, ErrorMatches, "not implemented yet")
+}